1. Field of the Invention
The present invention relates to an information processing apparatus, information processing method, information processing system and information processing program that perform control according to, for example, a key input or the like made by a user.
2. Description of the Related Art
In the past, a person generally uses an operation button or a touch panel in making some input. A touch panel is combined with a flat display, such as an LCD (Liquid Crystal Display), so that an operational input is made as if button icons or so displayed on the display screen were depressed.
Such an input operation is premised on contacting with or pressing the flat surface of an operation button top or the screen of the touch panel. Accordingly, the limited operation, namely contacting with or pressing the flat surface, is an operational input. In addition, the technique is limited to an application which enables contact with a flat surface.
This has raised problems such that contact- or pressure-caused vibration or force interferes with the performance of the device, and stains or damages the contact surface.
As an improvement on those problems, a proximity detection information display apparatus is disclosed in Patent Document 1 (JP-A-2008-117371) by the present applicant. Patent Document 1 describes the use of a sensor with a sensor panel which has a plurality of line electrodes or point electrodes arranged in, for example, two orthogonal directions.
The sensor detects the distance between the sensor panel surface containing a plurality of electrodes and a detection target spatially separated from the panel surface, e.g., a human hand or finger, by detecting a capacitance corresponding to the distance for those electrodes.
That is, the capacitance between each of a plurality of electrodes of the sensor panel and the ground changes according to the spatially separated distance between the position of a human hand or finger and the panel surface. In this respect, a threshold value is set for the spatial distance between the position of a human hand or finger and the panel surface, and it is detected if the finger has moved closer to or away from the panel than that distance by detecting a change in capacitance corresponding to the distance.
Patent Document 1 discloses a technique capable of enhancing the sensitivity of detecting the capacitance by changing the interval between electrodes which detect the capacitance according to the distance between the detection target and the sensor panel surface.
According to the preceding technique proposed, a switch input can be made without touching the sensor panel. Because the sensor panel has a plurality of line electrodes or point electrodes arranged in two orthogonal directions, the motion of a hand or a finger in a direction along the panel surface can be detected spatially, bringing about a characteristic such that an operational input according to the motion of the hand or finger within the space can also be made.